OBJECTIVE: To study the epidemiology of carcinoma of the esophagus to test previously suggested causal hypotheses and association, to discover new associations and to delineate the characteristics of the high risk groups. The study proposed is a large case control study to be performed prospectively in Los Angeles County. It has been designed to permit simultaneous examination of multiple antecedent risk factors. APPROACH: Cases with cancer of the esophagus will be identified by the LAC/USC Cancer Surveillance Program. A questionnaire has been designed to obtain data on environmental exposures - tobacco and alcohol consumption, diet, occupation and medical history and treatment. It will be administered to both cases and neighborhood controls as soon as possible after the cases have been diagnosed. Standard matched pair analyses of multiple variables will be performed on the data from the questionnaire.